In B/X, monsters have more various attacks. For example, an Owlbear has: 2 claw/1 Bite that deals 1d8 damage each. But how does this work? Can they use one attack per turn or all their attacks in one ...

I'm confused about how to DM the first round of an encounter using Moldvay's rules, specifically, when is the DM supposed to use the Monster Reaction table on page B24.
Say a party encounters a group ...